1. Field of the Invention
The present invention relates to a liquid dilution device to dilute a special liquid, more particularly relates to a liquid dilution device in which a jet for adjusting a dilution factor can be cleaned.
2. Description of the Related Art
Conventionally, liquid dilution devices are widely used to mix a special liquid such as a chemical liquid or detergent with tap water, for sterilization or disinfection of tableware or fresh vegetables at the time of cleaning. As disclosed in Japanese Patent No.3149166 and so on, for example, the conventional liquid dilution device includes a diluent passage for allowing passage of water (tap water), a negative pressure generating section formed in order to generate negative pressure midway along the diluent passage, and a liquid introduction passage connected at one end to the negative generating section and connected at the other end to a special liquid tank, formed inside a body. By causing a liquid, such as water or the like, to flow in the diluent passage, negative pressure is generated at the negative pressure generating section, so that the special liquid from a special liquid tank is introduced into the diluent passage, and the special liquid is mixed with the water to be diluted.
Since it is desirable for such a liquid dilution device to change the dilution factor depending on the special liquid, various methods for changing the dilution factor have been considered.
For example, it has been considered to fix a jet in a hose connecting the special liquid tank to the liquid dilution device, and to interchange these jets. However, there is a problem that the interchanging of the jets by a user is inferior with regards to efficiency and interchangeability.
Therefore, it has been considered to provide a dilution factor switching means in the liquid dilution device itself. A liquid dilution device of the related art provided with a dilution factor switching means is shown in FIG. 15 and FIG. 16, and the switching means is shown in FIG. 17.
One diluent passage 61 is formed inside the body 60, for introducing a diluent such as water. The diluent passage 61 includes a venturi section 62 formed at some midpoint as a negative pressure generating section, and a diffusion section 63 formed at a downstream side of this venturi section 62 as a negative pressure generating section having a diameter larger than that of the venturi section 62. A connecting passage 64 for connecting the diffusion section 63 to the outer side of the body 60 is formed in the body 60.
A disk 66, which is held between the body 60 and a holding member 65, is provided on the outer side of the body 60 at the side of an opening section of the connecting passage 64, as the dilution factor switching means. The disk 66 is rotatably attached to the body 60 and the holding member 65 through a bearing 68, centering around a shaft (bolt) 67 as a fixing means for fixing the holding member 65 to the body 60. As shown in FIG. 17, a plurality of jets 69, respectively varying in diameter, is formed in the disk 66 on the same radius from a rotation center position.
In addition to the holding member 65, a liquid introduction device 70 is provided on the opposite side to the body 60 so as to sandwich the disk 66, and the liquid introduction device 70 is fixed to the body 60. The liquid introduction device 70 includes a first body 71 and a second body 72, and a liquid supply passage 73 connecting to a special liquid tank, not shown, is formed inside the first body 71 and the second body 72. The liquid supply passage 73 is connected to the dilution passage 61 through the jet 69 formed in the disk 66 and the connecting passage 64 of the body 60.
A ring-shaped seal member 74 is attached at a position of the body 60 facing the disk 66 and surrounding the connecting passage 64. The ring-shaped seal member 74 is for preventing leakage of water from the dilution passage 61 through the connecting passage 64 from a joining surface of the body 60 and disk 66. A ring-shaped seal member 75 is attached at a position of the first body 71 of the liquid introduction device 70 facing the disk 66 and surrounding the liquid supply passage 73. This ring-shaped seal member 75 is for preventing leakage of a special liquid from the liquid supply passage 73 from a joining surface of the first body 71 and disk 66. An elastic member 76 is provided at a position of the body 60 facing the disk 66 and being far from the seal member 74, and an elastic member 77 is provided at a position of the holding member 65 facing the disk 66 and being far from the seal member 75. These elastic members 76 and 77 prevent the disk 66 from leaning towards either the body 60 or the holding member 65.
The connecting passage 64 of the body 60 and the liquid supply passage 73 of the liquid introduction device 70 are connected through the jet 69 by lining up one of the plurality of jets 69 formed in the disk 66. In this way, when the connecting passage 64 and the liquid supply passage 73 are connected through the jet 69, the special liquid is introduced from the liquid supply passage 73 into the dilution passage 61 by negative pressure generated in a diffusion section 63 of the dilution passage 61. Here, it is possible to vary the flow amount of the special liquid introduced into the dilution passage 61 to change the dilution factor, by rotating the disk 66 to line up one of the plurality of jets 69 with the connecting passage 64 and the liquid supply passage 73.
With the liquid dilution device which comprises only one jet 69 to adjust the flow amount, or comprises the plurality of jets 69 to adjust the flow amount in the dilution factor switching means 66, with the passage of certain time after the jet 69 is once used, there arises a problem that the desired dilution factor cannot be obtained because the special liquid may be dried out, the jet 69 may be stuck, and the jet 69 may be choked.
The present invention was devised in the light of the abovementioned problem. It is an object of the present invention to provide a liquid dilution device which makes it possible to prevent a jet for adjusting the flow amount of the special liquid from choking.